Vincent Nguyen

Document Type

Honors Thesis


Detection of population density is a form of communication for certain phytobacteria that usually involves the association of small diffusible chemical signals, particularly N-acyl homoserine lactones. It is pondered whether or not this molecule and the phytotoxin, coronatine, play a significant role in the directional motility of the wild type (Pst DC3000) and mutant strains (Pst DC3118, Pst DB29, and Pst psy/IR-) of Pseudomonas syringae pv. tomato on the adaxial surface of Arabidopsis thaliana leaves. A leaf assay and in vivo experimentation by spotting a set of leaves for each bacteria and making an imprint on an agar plate following a designated time-point was conducted to observe for existence of such phenomenon. Patterns of colony formation were noted and distance from the spotting point to the farthest point traveled was measured in millimeters to make a comparison between the mutant strains to the wild type bacterium. Based on the average distance calculated per time point and for all time points, data suggest that there is not a statistical significance in directional motility between the wild type strain and the mutant strains. Therefore, AHL and coronatine does not seem to contribute to directional motility aside from their standard roles. This determination is not conclusive, however, due to few trials and sample size. Since the objective was also to develop a new protocol, further investigations and studies must be replicated to engender conclusive results and suggestive implications.

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Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.



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